I've been pretty lucky so far with outfitters. From what I've found sometimes the most expensive isn't always the best. There are many reputable outfitters out there but there are also some sleazy outfits. There are a couple good sources for good outfitters that I know of. One is Cabela's TAGS and the other is the NAHC outfitter list.
But even these are not 100%. You need to get references, lots of them. Even talk to the game commission in that state and see if there are any bad reports on an outfitter you're interested in. And if its a bowhunt its best to get an outfitter that has bowhunting success.
If you decide on a DIY hunt you need to plan several extra days just for scouting the area.